Radiators are conventionally employed to cool the coolant for liquid cooled engines and most frequently are found in vehicles. In typical vehicle usage, the engines are turned off and on and when so cycled, go from an ambient or relatively cool temperature to an operating temperature and back. And of course, as the engine is intended to propel the vehicle, the vehicle will move the engine and the radiator over the underlying terrain.
The cycling that goes with turning an engine on and off provides severe strain on the radiator. As the coolant heats up following initiation of operation of the engine, the pressure within the coolant system increases. When the engine is turned off and the coolant begins to cool, the pressure will begin to decrease. This of course means that various radiator components are subjected cyclically to varying pressure and must be capable of repeatably withstanding such cycling.
The off-on cycling of the engine also thermally stresses the radiator components. In particular, as coolant temperature increases or decreases, radiator components in thermal contact therewith will expand or contract and the since the expansion and contraction is generally not uniform across the entire radiator, thermally induced stresses will occur.
Needless to say, the vibration that is involved as a vehicle traverses the underlying terrain also physically stresses all parts of the vehicle, including the coolant system and the radiator therein.
In order to both minimize weight as well as to maximize thermal efficiency and minimize component cost, fins and tubes employed in radiators are made as thin as possible. This of course reduces their physical strength. Given the stresses that appear in the environment in which the radiator is used, it is necessary that there be some means of support for the radiator and its components.
Heretofore, conventional radiators to be used in heavy duty vehicular applications have been known as "bolted radiators". In these constructions, metallic tanks also act as frame members and are bolted by as many as fifty or more bolts to each of the two headers of a radiator core and side pieces, with or without one or more additional frame members which may be employed to locate the headers with respect to one another and to strengthen the assembly against failure induced by thermal cycling. In plate fin constructions, the plate fins provide support against pressure cycling failure. Where lesser cost serpentine fins are used, the problem of pressure cycling failure remains. Vibration in the environment of use is always a concern.
While such constructions work well for their intended purposes, they are difficult to assemble because of the many bolts required and leakage at the header to tank interfaces can be a problem. Moreover, the constructions do not provide a great deal of flexibility in terms of allowing one type of unit to serve a variety of differing vehicles without substantial modification
The present invention is directed to overcoming one or more of the above problems.